SONY MDS-JA50ES

Commentary

A prestige model of the ES series MD deck with DSP for ATRAC and wide bit stream technology.

In order to maximize the use of the ATRAC audio compression technology and to further improve sound quality, we have introduced a wide bit stream technology using a newly developed ATRAC DSP. This technology uses the new ATRAC DSP, which is the 4.5 generation, as a key device, with 20-bit input / output and 24-bit (data) × 24-bit (coefficient) arithmetic operations.
The MDS-MDS-JA50ES divides the audio band into three blocks : low, medium, and high. Floating operation is performed for each block. The block with large data is left as it is, and the block with small data is operated by raising the level of each block. Thus, reproduction of low-order bits, which had been truncated in the past, is made possible, and reproducibility of minute level music signals is improved. This enables recording and playback with 20-bit accuracy and a wide dynamic range.
The A/D converter is equipped with a 24-bit delta-sigma (delta-sigma) A/D converter with high precision oversampling.

An adaptive high-frequency control technology has been introduced to improve the reproducibility of the high-frequency range and the sense of natural sound spread.
This algorithm was developed as an algorithm that effectively uses a limited amount of data by controlling the high-frequency range according to the input signal based on the human auditory sense. For example, with this algorithm, for signals containing regular frequency components, for which distortion is felt to be worse when the number of quantization bits is small, the quantization bits are limited to between about 15 kHz and 22.05 kHz to increase the quantization bits. On the other hand, for signals containing complex frequency components that are less affected by insufficient quantization bits, the reproduction band is extended to higher frequencies to improve the reproducibility of the high-frequency range.
By combining this adaptive high-frequency control technology with the expansion of the operational tone, the accuracy of signal processing has been improved, and the total harmonic distortion rate has been improved by approximately 8 dB compared with conventional methods.

It is equipped with a sampling rate converter that automatically converts 32 kHz and 48 kHz sampling 48 kHz to 44.1 kHz and enables digital recording with quality degradation.

The D/A converter uses the current pulse D/A converter used in Sony's ES series CD players. The current pulse output as voltage is replaced with a current that is less affected by voltage-induced noise and transmitted. It has a stable current source and is not affected by voltage fluctuations, enabling stable low-frequency playback.

The power supply section uses an R-core transformer with no breaks in the iron core of the transformer and a circular doughnut type section to reduce magnetic flux leakage and vibration.

BASC panel is used for the front panel. BASC is an acronym for B (Brass), A (Aluminum), S (Steel), and C (Construction). It pursues structural accuracy and eliminating resonance that cannot be achieved by combining molded parts.
In the case of molded parts, the points that can be fixed with screws are limited to a certain extent, and resonance remains. In addition, precision is also insufficient due to expansion and contraction when the parts are molded. On the other hand, metal parts can be processed with high precision, so high structural accuracy can be pursued. In addition, connecting points of parts can be installed at important points. In addition, by combining three types of metals with different natural frequencies, the effect of stopping vibrations from each other can be obtained.
The MDS-JA50ES has a steel base with a brass guide that is connected to an aluminum panel plate, and the volume and other parts are attached to the brass guide so that the face protrudes from the aluminum panel.
In addition, most of the volume knobs and buttons are made of aluminum.

FB chassis is adopted for the chassis. Metal material with sufficient strength and thickness is used. The whole chassis is firmly fixed as one box by surrounding brems and beams passed in front and back. By combining members of different shapes and sizes in each part, natural vibration is mutually cancelled, and vibration of the whole chassis is reduced.
In addition, the chassis of the mechanical deck is made of metal material with sufficient thickness. Strong metal is combined around the base unit to form a single shell, making the structure not only rigid but also resistant to vibration.

By using an eccentric insulator whose mounting hole to the chassis is offset from the center, signals transmitted from the outside are mutually canceled, making it difficult for signals to be transmitted to the chassis. As a result, it is effective in damping vibration components in the middle and high frequency range, which affect auditory sense in particular.

Equipped with a digital REC level control, it can be controlled from - ∞ dB to a maximum of + 12 dB around a gain of 0 dB. In addition, it is equipped with a non-clip circuit that checks the level of the input source, and if a clip (saturation state) occurs due to gain over, the volume value is gradually reduced so as not to become unnatural while the clip state continues.
You can also select a volume change curve for adjusting the digital recording level. You can choose from three curves, Linear, Sin, and Log, depending on the mood of the song.

Equipped with a V. C. (Variable Coefficient) digital filter, it can be used during MD playback to change the cutoff characteristics of the digital filter to obtain subtle sound changes. There are four positions of the Variable Digital Filter to adjust the sound quality according to your preference.

It is equipped with a variable level sink function that can select the detection level and detection time for determining silence.

Equipped with an evenly spaced track marking function that allows automatic track marking every 1 or 5 minutes.

It has a name copy function that allows you to copy the names of songs and discs on the same disc.

Equipped with a resume function that allows playback from the next position even if the power is turned off during playback.

It is equipped with a peak hold function to check the maximum level during recording and playback.

Equipped with Digital Out tone switching function (20bit/16bit) which can switch the tone of digital output.

Equipped with fade-in / fade-out function.

It is equipped with a time machine recording function. If you press the multi-jog dial in the recording pause state, the sound recorded up to 6 seconds before is recorded on the disk.

Equipped with an UNDO function that allows you to cancel the last edit operation and redo it.

It is equipped with a rehearse function that allows you to check edit points in COORDINATE or DIVIDE.
To move edit points, you can fine-tune the DIVIDE edit point in minutes, seconds, or frames (approximately 0.01 seconds).

Equipped with an A-B ERASE function that allows you to erase between two specified points in a song.

It is equipped with a title function that can record up to approximately 1,700 characters of disc names and song titles on the disc. Katakana characters can be used in addition to conventional alphabets, numbers and symbols.
Input can be made with the main unit and remote control even during recording and playback. Direct input is possible by using the remote commander for katakana input (sold separately).

Mono format discs are play-only.

The SCMS (Serial Copy Management System) allows digital recording only for one generation and does not allow digital recording for two or more generations.

There were 2 kinds of models, gold and black.

Wireless remote control is included.

Model Rating

Type	MD deck
A/D converter	24-bit ⊿∑
D/A converter	Current pulse D/A converter Variable (V. C.) filter
Recording system	Magnetic field modulation overwrite system
Regeneration system	Noncontact optical
Laser	Semiconductor laser (λ = 780 nm)
Number of revolutions	Approximately 400 ~ 900 rpm
Coding system	ACIRC
Sampling frequency	44.1kHz
Voice compression system	ATRAC
Modulation system	EFM (8-14 modulation)
Number of channels	2 Channel
Recording and playback time	Stereo : up to 74 minutes Monaural : up to 148 minutes
Frequency characteristic	5 Hz to 20 kHz ± 0.3 dB
Dynamic range	105 dB or more (during playback)
Signal-to-noise ratio	108 dB or more (during playback)
Total harmonic distortion factor	0.002% or less (during regeneration)
Wow and flutter	Measurement limit (0.001% W peak) or less
Input terminal	Line : 1 system Optical digital : 2 systems Coaxial digital : 1 system
Output terminal	Line : 1 system Optical digital : 1 system Headphone : 1 system
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	22W
External dimensions	Width 430x Height 125x Depth 375 mm
Weight	Approx. 14.3 kg
Attachment	Wireless Remote Control RM-D14M
Sold Separately	Katakana Input Dedicated Remote Commander RM-D10P (¥ 7,500)